I purchased and installed the coolant filter on my LBZ it had roughly 110,000 miles on it when installed and the coolant had been flushed 2 times by my local shop that has a vacuum flush system. I switched form the god awful Dex Cool pink stuff that came in the truck from the factory at 9,000 miles to the Amsoil Yellow stuff. I also run RMI-25 and put 8 ounces of it in when I change the filter every 30,000 miles, well except for the first filter change which I did at 10,000 miles.
I did not take any pics of the first filter when we cut it open. there was sand and metal flakes in the filter and also some dark patches around the element. It was not too dirty, as I owe the Amsoil and the RMI-25 a lot of accolades as the combo keeps my system flowing well. I have changed the filter 3 times and I now have 160,000 miles on it. I have not cut any other filter open, all I can tell you is my resivoir tank is clean as the day I bought the truck. There is no visible discoloration in the fluid and the filter flows really well.
I think it was worth the money. I had an 01 LB7 and I had to replace the $1,100 water pump in it at 135,000 miles and it was crudded up and looked awful, when I went back to the Tech to see it. That pink stuff is the worst stuff there is. I will post if my current water pump fails, but I cant see how right now with as clean as the sysytem is, and as slick as the Amsoil and RMI-25 makes the fluid.
$1,100 and a 4 hour job, or $150 for the kit and extra filters, seems like a no brainer to me.
http://www.dieselsite.com/index.asp?PageAction=VIEWPROD&ProdID=605
